10db attenuator » History » Version 5
dexter, 02/19/2016 10:47 PM
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| 2 | == 10dB attenuator == |
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| 4 | 4 | dexter | The attunator that is shown here has a damping of 10dB that means it turns the 30mW output of the BS11 into 3mW output. Please note that 10dB is only an example. The attenuator is designed to be configured to any damping factor. |
| 5 | 1 | dexter | |
| 6 | [[Image(10dB_attenuator.jpg,width=300px)]] |
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| 8 | 4 | dexter | The first thing you should do is calculating the resistor values here: |
| 9 | 1 | dexter | |
| 10 | 4 | dexter | Resistors values can be calculated at: |
| 11 | http://www.aroesner.homepage.t-online.de/d-glied.html |
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| 12 | 3 | dexter | |
| 13 | 4 | dexter | The values you get will not match to the resistor values you can by. That is the reason why the PCB has 3 resistors in series to form one of the resistors you have calculated with the script. |
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| 15 | [[Image(attenuator_schematic.png,width=300px)]] |
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| 17 | 4 | dexter | [[Image(attenuator_layout.png,width=300px)]] |
| 18 | 5 | dexter | |
| 19 | When everything is tested twice you should seal the attenuator with a HF-Tin. I used a commercially available tin-box-cover. Please note that on the photo only the corners of the tin are soldered. That is because the attenuator was just in the development phase and we easyly wanted to be able to remove the tin to recycle the components. |
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| 21 | [[Image(10dB_attenuator_sealed.jpg,width=300px)]] |
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| 23 | == Testing == |
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| 24 | Our testcase was a spectrum analyser with an atenna and the BTS in the other room. All tests were done with the original antenna and without the attenuator: |
